require_relative './helpers'

module AnnotateRoutes
  class HeaderGenerator
    PREFIX = '== Route Map'.freeze
    PREFIX_MD = '## Route Map'.freeze
    HEADER_ROW = ['Prefix', 'Verb', 'URI Pattern', 'Controller#Action'].freeze

    class << self
      def generate(options = {})
        new(options, routes_map(options)).generate
      end

      private :new

      private

      def routes_map(options)
        result = `rake routes`.chomp("\n").split(/\n/, -1)

        # In old versions of Rake, the first line of output was the cwd.  Not so
        # much in newer ones.  We ditch that line if it exists, and if not, we
        # keep the line around.
        result.shift if result.first =~ %r{^\(in \/}

        ignore_routes = options[:ignore_routes]
        regexp_for_ignoring_routes = ignore_routes ? /#{ignore_routes}/ : nil

        # Skip routes which match given regex
        # Note: it matches the complete line (route_name, path, controller/action)
        if regexp_for_ignoring_routes
          result.reject { |line| line =~ regexp_for_ignoring_routes }
        else
          result
        end
      end
    end

    def initialize(options, routes_map)
      @options = options
      @routes_map = routes_map
    end

    def generate
      magic_comments_map, contents_without_magic_comments = Helpers.extract_magic_comments_from_array(routes_map)

      out = []

      magic_comments_map.each do |magic_comment|
        out << magic_comment
      end
      out << '' if magic_comments_map.any?

      out << comment(options[:wrapper_open]) if options[:wrapper_open]

      out << comment(markdown? ? PREFIX_MD : PREFIX) + timestamp_if_required
      out << comment
      return out if contents_without_magic_comments.size.zero?

      maxs = [HEADER_ROW.map(&:size)] + contents_without_magic_comments[1..-1].map { |line| line.split.map(&:size) }

      if markdown?
        max = maxs.map(&:max).compact.max

        out << comment(content(HEADER_ROW, maxs))
        out << comment(content(['-' * max, '-' * max, '-' * max, '-' * max], maxs))
      else
        out << comment(content(contents_without_magic_comments[0], maxs))
      end

      out += contents_without_magic_comments[1..-1].map { |line| comment(content(markdown? ? line.split(' ') : line, maxs)) }
      out << comment(options[:wrapper_close]) if options[:wrapper_close]

      out
    end

    private

    attr_reader :options, :routes_map

    def comment(row = '')
      if row == ''
        '#'
      else
        "# #{row}"
      end
    end

    def content(line, maxs)
      return line.rstrip unless markdown?

      line.each_with_index.map { |elem, index| format_line_element(elem, maxs, index) }.join(' | ')
    end

    def format_line_element(elem, maxs, index)
      min_length = maxs.map { |arr| arr[index] }.max || 0
      format("%-#{min_length}.#{min_length}s", elem.tr('|', '-'))
    end

    def markdown?
      options[:format_markdown]
    end

    def timestamp_if_required(time = Time.now)
      if options[:timestamp]
        time_formatted = time.strftime('%Y-%m-%d %H:%M')
        " (Updated #{time_formatted})"
      else
        ''
      end
    end
  end
end